I passed first 5 Javascript missions without any problems. But now I have problem with Javascript mission 6. I don't know what to do(It's about 2 weeks that I'm in this mission ). just help me with some clues or something useful,tnx.

In the description, they're talking about unused code and new code. If you look at the source, you see a piece of JavaScript code and you see a link. That's one of the two pieces of JavaScript and a link. Just follow the link, guess what you'll find there....In general, if there's a link given, you usually have to do something with it.